Meter type relay having levers for resetting its contact arm



Aug. 11, 1953 E. B. MARSHALL 2,648,735 METER TYPE RELAY HAVING LEVERS FOR RESETTING ITS CONTACT ARM Filed Dec. 16, 1949 2 Sheets-Sheet 1 FIG. l

FIG. 2

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37 I k J INVENTOR E. B. MARSHALL ATTORNEY E. B. MARSHALL METER TYPE RELAY HAVING LEVERS FOR RESETTING ITS CONTACT ARM 2 Sheets-Sheet 2 Filed Dec. 16, 1949 FIG. 4

INVENTOR E. B. MARSHALL v ATTORNEY Patented Aug. 11, 1953 METER TYPE RELAY HAVING LEVERS FOR RESETTING ITS CONTACT ARM Emil B. Marshall, Chicago, Ill., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application December 16, 1949, Serial No. 133,379

7 Claims.

This invention relates to a meter type relay having levers for resetting its contact arm and more particularly to a control device for preventing the false operation of the contact arm in response to actuation of the resetting levers.

In one kind of meter type relay, a contact arm, oscillatable with the moving coil of the relay, has a magnetic rider which is engageable with either of a pair of magnetized contacts mounted on opposite sides thereof for completing an operating circuit through the contact arm and the magnetized contacts. The magnetized contacts serve to maintain the magnetic rider and contact arm in engagement therewith and a pair of resetting levers operatively connected to a solenoid plunger and controlled by the actuation of the solenoid are provided to restore the contact arm to a neutral zero position intermediate the magnetized contacts. An apparent attraction between the resetting levers and the contact arms operates at times to cause the contact arms to follow one of the resetting levers on the return movement of the resetting levers after they have been actuated to restore the contact arm to zero position and this false movement of the contact arm establishes contact with the magnetized contact and erroneously completes the operating circuit.

It is an object of the present invention to provide a meter type relay having a movable contact arm and resetting levers for restoring the contact arm to a neutral zero position a control device for preventing the false movement of the contact arm in response to the actuation of the resetting levers.

This invention contemplates the addition of a switch device to the above-described meter type relay for short-circuiting the moving coil for a short interval of time during the initial portion of the return movement of the resetting levers to utilize the damping effect of the shorted coil to restrain the contact arm from movement as the resetting levers move away from the contact arm, the shorting switch being in the form of a flexible contact spring mounted on the solenoid plunger for movement therewith and engageable with a pair of binding posts electrically connected to the moving coil.

Other objects and advantages of the invention will be apparent by reference to the following detailed description thereof and the accompanying drawings illustrating a preferred embodiment in which Fig. 1 is a front elevational or face view of a meter type relay embodying the present invention;

Fig. 2 is a, cross sectional view of the device shown in Fig. 1 with parts broken away and parts shown in elevation and taken on the line 2-2 of Fig. 1;

Fig. 3 is a vertical longitudinal sectional view taken on the line 3-3 of Fig. 1; and

Fig. 4 is a diagrammatic perspective view of a portion of the relay.

The invention as shown herein is applied to a meter type relay similar to the embodiment illustrated in Figs. 4, 5 and 6 of the patent to A. H. Lamb No. 2,062,915, issued December 1, 1936, on a Control Device.

The relay comprises a base I0, on which is mounted a permanent magnet [2 between the poles of which is pivotally supported a coil I4 of a moving system including a needle pointer or contact arm IE, on one end of which is mounted a magnetic rider I8. The rider [8 is movable into engagement with either one of a pair of magnetized contacts 20-20 supported by brackets 22-22 on the base in the path of movement of the rider [8 and on opposite sides thereof to close either of a pair of operating circuits through the contact arm l6 and the contacts 20. When the contact arm IS, in response to a flow of current in the control circuit and the coil, is moved from a normal neutral or zero position midway between the contacts 20 into an operative position with the rider in engagement with one of the magnetized contacts 20, the magnetic attraction between the contacts 20 and the rider [8 serves to retain the contact arm I6 in such operative position.

A resetting mechanism is provided for separating the rider l8 from the magnetic contact 20 and restoring the contact arm [6 to a neutral or zero position and comprises a pair of hell crank levers 25-25 pivotally supported in brackets 21 mounted on the base [0 on opposite sides of the contact arm I6 and having buffers 28-28 at their outer ends 30-30 engageable with the contact arm IS. The other ends 3l-3l of the bell cranks 25 are directed inwardly toward each other and fit in a groove in a head 32 formed on a bolt 33, which is secured to the core or armature plunger 34 of a solenoid 35 secured to the base I0. A spring 37 mounted in the closed end of the bore of the solenoid 35 engages one end of the armature plunger 34 and moves it in one direction against a stop 39 formed in the base 10.

In response to the energization of solenoid 35, the plunger 34 is retracted, causing the resetting levers 25 to be actuated to move the ends 30-30 thereof and the buffers 28-28 toward each other,

the contact arm [6 being engaged by one of the buifers and moved from its operative position to its neutral position, where it is engaged on opposite sides thereof by both of the buffers 28. Thus, in response to the energization of the solenoid 35, the bell crank levers 25 are oscillated and the ends 30 thereof are moved in opposite directions toward each other to reset the contact arm It to its neutral position and, upon the deenergization of the solenoid 35, the spring 31 moves the plunger 34 to its normal position, shown in Fig. 2, which movement eifects the return of the bell crank levers to their normal separated or inoperative position, also shown in Fig. 2.

It frequently happens that, because of the attraction between the contact arm I6 and the ends of the bell crank levers 25 or the buffers 28 thereon, after the resetting mechanism has been actuated and the bell crank levers are returning to their normal operative positions, the contact arm 16 will be attracted by one of the bell crank levers and carried therewith to a position where the rider 18 comes within the magnetic influence of the contact 20 and establishes contact therewith. This false actuation of the contact arm 16 and the erroneous closing of the operating circuits through the contact arm I6 and the contacts 20 is highly undesirable and, in order to prevent these false operations in response to the returning movement of the bell crank levers 25, a control device is provided for restraining the coil [4 and the contact arm it against movement while the lever ends 38 are being separated therefrom. The control device comprises switch means 33 for short-circuiting the coil M for a predetermined short interval of time during the initial portion of the return movement of the resetting levers 25 to utilize the damping effect of the magnetic forces opposing the movement of a closed coil in a magnetic field to restrain the contact arm Hi from movement while the lever '25 are separating therefrom.

Any suitable switch means maybe used for shorting the coil l4 durin the initial portion of the return movement of th resetting levers 25. In the embodiment illustrated, there is provided a T-shaped member 45 secured at one end to the end of the bolt 33 on the solenoid plunger 34 for movement therewith. The cross arm 56 on the member 55 may engage and bridge a pair of binding posts or terminals 48 in the control circuit to which the coil it is electrically connected but preferably the cross arm it is adapted to engage contact members til-55 extending from the binding posts 58 to short-circuit the coil l4. Either the member 45 or the members 50, 01' both, of the switch means it may be flexible to permit a predetermined movement of the plunger 3 after the member ie has engaged the contact members 5% and shorted the coil M. The cross arm 45 of the switch member in the normal position of the resetting mechanism is spaced a predetermined distance from contacts 50 and, upon energization of the solenoid and the movement of the plunger as in one direction, is adapted to engage the contact member 50 to short the coil id as the plunger 36 nears the end of its stroke and as the ends 30 of the levers 25 near the end of their movement, resetting the contact arm to zero position. The cross arm 45 remains in engagement with the contacts 50 and the coil l4 remains shorted as the plunger 34 completes the remainder of its stroke and the ends of the levers 25 complete the remainder of their resetting movement and the contact member 45 remains in engagement with the contacts 50 during the initial portion of the return stroke of the plunger 34 and during the initial portion of the return movement of the levers 25. Thus the coil Hi is shorted and the contact arm I6 is restrained from movement for a short interval of time during which the ends 30 of the resetting levers 25 are moved away from the contact arm IS a distance sufficient to eliminate any attractive influence which might occur between the ends 30 of the levers 25 and the contact arm 16. After this initial predetermined interval of return movement has been traversed by the plunger 3 4i, and the ends 30 of the levers are completely separated from the contact arm I6, the cross arm at of the switch member 45 is disengaged from the contacts 50 and the coil is thereby restored to its normal or unshorted condition and the levers 25 continue their return movement to their normal inoperative position without exerting any further eifect on the contact arm.

It will be apparent, from the foregoing, that the current passing through a control circuit in which the terminals 58 and the coil M are connected serves to create a magnetic force which rotates the coil I4 about its axis of rotation and swings the contact arm it into its operative position to close the operating circuit through the contact 29, the rider i8 and the contact arm, [6. When it is desired to restore the contact arm to its neutral position and to break the operating circuit, the solenoid is caused to be energized, which actuates the resetting mechanism and causes the ends so of the resetting bell cranks 25 to move toward each other and return the contact arm Hi to its neutral position. The switch member near the end 01 the movement of the plunger 34 in one direction, and movement of the lever ends 30 toward each other, short circuits the coil It while the lever ends 31] complete their resetting movement, and the member 45 maintains the coil Hi shorted to prevent movement of the contact arm it during the initial portion of the return movement of the lever ends 30 to insure the separation of the lever ends 33 from the contact arm It, after which the coil is unshorted and the resetting arms and the plunger return to their normal inoperative position while the contact arm 16 remains in its neutral position.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerousother arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is: i

1. In a meter type relay, the combination of a coil movable in a magnetic field, a contact arm mounted for oscillatable movement with said coil, a magnetized contact mounted in the path of movement of said contact arm and engageable thereby, a resetting lever movable from a normally inoperative position to an operative position and engageable with said contact arm to separate the contact arm from said magnetized contact and restore it to a normal neutral posi tion, means for actuating said resetting lever, switch means electrically connected to said coil, and means operable in timed relation with the movement of said resetting lever for actuating said switch means to short said coil during a predetermined interval of the movement of said lever.

2. In a meter type relay, the combination of a coil movable in a magnetic field, a pair of terminals to which the ends of said coil are connected, a contact arm mounted for oscillatable movement with said coil, a magnetized contact mounted in the path of movement of said contact arm and engageable thereby, a resetting lever movable to and from a normal inoperative position and an operative position and engageable with said contact arm for disengaging said arm from said magnetized contact and moving it to a normal neutral position, a bridging member, means guiding said bridging member for movement into and out of engagement with said terminals to short said coil, and means for actuating said bridging member in timed relation with the movement of said resetting lever to cause the short-circuiting of the coil during a predetermined interval of movement of said resetting arm.

3. In a meter type relay, a coil movable in a magnetic field, a contact arm mounted for movement with said coil, a magnetized contact mounted in the path of movement of said contact arm and engageable thereby, a resetting lever operable to separate the contact arm from the magnetized contact and move it to a normal neutral position, means including a reciprocable member for actuating said resetting lever, a pair of yieldable terminal members to which the ends of said coil are connected, and a contact member mounted for movement with said reciprocable member and movable thereby into engagement with said yieldable terminals during a predetermined portion of the movement of said reciprocable member to short the coil during a predetermined interval of movement of the resetting lever.

4. In a meter type relay, a coil movable in a magnetic field, a pair of terminals to which the ends of the coil are connected, a contact arm mounted for oscillatable movement with said coil, a magnetized contact mounted in the path of movement of said contact arm and engageable thereby, a resetting lever operable to disengage the contact arm from said magnetized contact and restore it to a normal neutral position, means including a reciprocable member for actuating said resetting lever, and a flexible contact spring mounted on said reciprocable member for movement therewith and operable to bridge said terminals and short circuit said coil during a predetermined portion of the movement of said member.

5. A meter type relay comprising a permanent magnet, a movable coil rotatably mounted in the field of said magnet, a contact arm mounted for movement with said coil, a pair of magnetized contacts mounted in the path of movement of said contact arm on opposite sides thereof, a solenoid having a movable armature, a pair of pivoted resetting levers mounted on opposite sides of said contact arm and operatively connected to said armature for actuation thereby to separate the contact arm from said magnetized contact and restore it to a normal zero position, and switch means electrically connected to said coil and actuatable by the movement of said armature to short-circuit said coil during a predetenmined interval of movement thereof.

6. In a meter type relay having a movable coil disposed in a magnetic field, a contact, a contact arm actuated by said coil and movable from a neutral position into engagement with said contact, and magnetic means for yieldably retaining said contact arm in engagement with said contact, the combination therewith of resetting mean including a lever for disengaging said contact arm from said contact and moving it to said neutral position, means for actuating said resetting means, switch means electrically connected to said coil for short circuiting said coil, and means operable in timed relation to said actuating means for actuating said switch means to short circuit said coil.

'7. In a meter type relay having a movable coil oscillatable in a magnetic field, a contact, a contact arm connected to said coil for movement therewith and movable from a neutral position into engagement ith said contact, magnetic means for yieldably retaining said contact arm in engagement with said contact, and a resetting lever movable from a normal position to another position and engageable during said movement with said contact arm to separate the contact arm from said contact and restore it to said neutral position, the combination therewith of switch means electrically connected to said coil for short circuiting said coil, and means for actuating said resetting lever and said switch means in a predetermined timed relation to each other.

EMIL B. MARSHALL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,062,915 Lamb Dec. 1, 1936 2.515314 Pierce July 18, 1950 

